Medical professionals getting NHS patients on a "heart bus" to be treated in a private clinic say they are saving about £1,000 a patient.
Corporate troubleshooter Sir Gerry Robinson spent six months analysing the coalition's planned changes to the NHS.
At Dr Kosta Manis's practice in Bexley, south-east London, heart complaint patients are seen by top cardiologist Dr David Brennand-Roper then bussed to Harley Street if they need further tests.
But Sir Gerry is concerned for the NHS's long-term future if its money continues to be spent in the private sector, saying the organisation is struggling to react to such competition.
Panorama: Gerry and the GPs is broadcast on BBC One, Monday 5 September at 2030 BST and then available in the UK on the